In the agriculture industry, agronomists often have to establish and follow an agro-environmental fertilization plan when cultivating a field. Such a plan determines the spreading limits for fertilizers for a given growing season. In order to best determine the fertilization needs of a particular area of land, it is often necessary to analyze soil samples in order to measure pH, and the concentration of several minerals, such as potassium, phosphorus, magnesium, aluminum and calcium, among others.
Current methods for analyzing samples involve four main steps: (1) collecting a soil sample; (2) transporting the sample to a laboratory and preparing it for analysis; (3) dissolving the sample chemically; and (4) analyzing the sample using methods such as Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-OES) or Flame Atomic Absorption Spectrometry (FAAS). These methods involve many different physical and chemical operations, both when preparing and analyzing samples. For example, many samples must be collected from several locations and prepared for transport to a lab. Next, the samples are subject to a laborious analyzing process involving drying, grinding, sieving, extracting and filtering.
Existing methods are both time consuming and expensive. For example, these methods require large individual samples (approximately 500 g) from various parts of a field which must each be transported to a lab. Once at the lab, analyzing the soil may require several different tests in order to analyze different characteristics of the soil. These tests can take a significant amount of time, making the turnaround time relatively slow.
In existing methods, there is also a significant risk that samples can become contaminated and/or confused. For example, identification information is often hand-written on sample containers, making identification difficult when the identification information contains mistakably similar characters, or when it is written with poor handwriting. What's more, in order to carry out a test, a portion of a soil sample must be transferred into a separate test container, creating an opportunity to introduce contaminants or lose track of a sample.
U.S. Pat. No. 8,286,857 describes a soil sample tracking system and method in which soil sample containers are provided with unique identifiers. The containers are used to temporarily store the soil samples until they are analyzed. The soil samples must thus be removed from their containers for analysis, and thus there is still a risk of mixing or contaminating the different soil samples.
These shortcomings have a significant impact on the use of such methods in practice. For example, due to the costs involved, many agronomists generally limit sampling to a single sample per field. This is not ideal, as it does not provide sufficiently fine-grained information about the soil characteristics of a field, and thus limits the effectiveness of an agro-environmental fertilization plan when it is based on that information.
Some improvements have already been made to the step of analyzing a sample in the laboratory. For example, soil can be analyzed using a method known as Laser Induced Breakdown Spectroscopy (LIBS), such as the method disclosed in U.S. Pat. No. 7,692,789. While this technology is an improvement in the lab, there is yet to be a practical method for using LIBS technology in the context of gathering several samples of soil from a field and managing data from the analysis of those samples.
There is therefore a need for an improved method and system which reduces costs and simplifies the overall process of sampling and analyzing soil by leveraging LIBS technology.